* Keerthy <j-keerthy@xxxxxx> [110215 20:53]:
> From: Richard woodruff <r-woodruff2@xxxxxx>
>
> This errata occurs when the ARDY interrupt generation is enabled.
> At the begining of every new transaction the ARDY interrupt is cleared.
>
> On continuous i2c transactions where after clearing the ARDY bit from
> I2C_STAT register (clearing the interrupt), the IRQ line is reasserted and the
> I2C_STAT[ARDY] bit set again on 1. In fact, the ARDY status bit is not cleared
> at the write access to I2C_STAT[ARDY] and only the IRQ line is deasserted and
> then reasserted. This is not captured in the usual errata documents.
>
> The workaround is to have a double clear of ARDY status in irq handler.
I'll add this to omap-testing for few days and then if no issue Ben
can merge this.
Regards,
Tony
> Signed-off-by: Richard woodruff <r-woodruff2@xxxxxx>
> Signed-off-by: Keerthy <j-keerthy@xxxxxx>
> ---
> drivers/i2c/busses/i2c-omap.c | 6 +++++-
> 1 files changed, 5 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
> index b605ff3..5b35cf4 100644
> --- a/drivers/i2c/busses/i2c-omap.c
> +++ b/drivers/i2c/busses/i2c-omap.c
> @@ -847,11 +847,15 @@ complete:
> dev_err(dev->dev, "Arbitration lost\n");
> err |= OMAP_I2C_STAT_AL;
> }
> + /*
> + * ProDB0017052: Clear ARDY bit twice
> + */
> if (stat & (OMAP_I2C_STAT_ARDY | OMAP_I2C_STAT_NACK |
> OMAP_I2C_STAT_AL)) {
> omap_i2c_ack_stat(dev, stat &
> (OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR |
> - OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR));
> + OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR |
> + OMAP_I2C_STAT_ARDY));
> omap_i2c_complete_cmd(dev, err);
> return IRQ_HANDLED;
> }
> --
> 1.7.0.4
>
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